X-ray apparatus



Dec. 4, 1934. H, R. AUSTIN x-RAY APARATUS Fileduarchzz, 1955 IFlef FIG-Z INVENToR y www ATTORNEY Patented Dec. 4, 1934 PATENToFFlcE X-RAY APPARATUS y Harold R. Austin, South Norwalk, Conn., assigner to M. W. Kellogg Co2, New York, N. Y.,

y poration of Delaware Application March 22,

11 Claims.

This invention relates in general to X-ray apparatus and in particular to the combination with X-ray apparatus of apparatus for treating the air that surrounds the X-ray apparatus to prevent ,1,5 interference with the normal operation of the `X-ray apparatus. 1

It has been found well nigh impossible to operate Xfray `machines, especially those of the character used in the examination of metal arlzo .ticles, continuously for any length of time during `days when 4the relative humidity and/ or thetemperature of the air are comparatively high. 1 The interruption in operation is due to the inability to y obtain the necessary high tension values across the .15 terminals ofj the X-raytube or tubes. The inability to build up the necessary high tension values, it

. is believed, is due to leakage through the exposed aswell as theinsulated portions of the circuit of the machine and discharge through the overload arrangements at voltage values much below those at which the overload arrangements are set to discharge. l

`'l'he .leakage through the exposed portions of the circuit of the machine and the discharge ".12 through the overload arrangements is due, at

`leastin part, to thehigh relative humidity of g .the air which so alters the dielectric constant of 4theair enveloping Vthe X-ray machine that the l conditions i. contemplated 4in, its design cannot be F attained@ The increased ionization at the times mentioned is also afactor in altering the dielecf y tric `constant of the air. [Theeffect ofthe increased ionization of the air is at all times appreciable because of `the fact that X-rayma- 5 chines, and especially those used in the examination of metal articles, are generally enclosed in housings which prevent circulation of theair. Thus the` quiescent air around theoverload arrangements andthe exposed parts of the circuit 0 of the machine may become veryhighly ionized andigreatly alter the dielectric constant of such The'leakage through the insulated portions of the circuit of the machine is due to the material increase in the conductivity of the insulation due to absorption bythe insulation gof 'even comparatively small percentages of moisture. It is known that small increases in moisture content of insulation material increasethe conductivityv of such ,50 material out of all proportion with the increase in moisture content. l f

Ithasbeen found that dust in the air that envelopes theHX-ray machines also interfereswith theirnormal operation. Dust in the air changes 11,;155 the dielectric constant'of` the air much in the 1933, Serial No. 662,042

(Cl. Z-34) same way as moisture does, and dust on the parts of the Xy-ray `machines provides leakage paths. Dust in the air will producethe undesired results just mentioned at any relative humidity value of the air.

l It is an object of this invention to` combine with X-ray apparatus means for acting upon the air v,which envelopes the apparatus to prevent undesired changes in the dielectric constant of such air. l l Y l It is afurther object `of this invention tocom- `bine with X-ray apparatus means under the control` of the apparatus for preventing undesired increase in the relative humidity of the air enveloping the apparatus. l

It is also an object of this invention to combine with X-ray apparatus means for constantly circulating the air which envelopes the apparatus, the circulating means including means for removing dust from the air and means for deionizing the air.

Other objects and advantages of the invention will be apparentirom a consideration-of the following descrptionhtaken with the accompanying drawing, in which f A l Fig` 1 isa front elevation of an Xl-ray machine `and its housing illustrating the invention,

Fig. 2 is a view similar to Fig. 1 but showing ,a different arrangement of the control for the air dehumidifying means, and .85

Fig. 3` is` an enlarged front elevation of the air treating device `with a portion of its casing broken away to show its internal construction, `and Fig. 4` is a fragmentary view similar to Fig. 2 showing another ,control arrangement for an air dehumidifying means.

For the purposes of this application the invention is disclosed in connection with an X-ray machine ofuthecharacter used in the examination of metallic articles, it being ofcourse, understood that v4the invention may be used with all types of X-ray machines and is not limited to rthe particular type of machine mentioned.

The X-ray machines of Figs. `1 and 2 are generally similar` and each includes a transformer l, a rectifying device 2, an X-ray tube 3, and alpair.; of spaced metallicspheres 4 which serve las an overload discharge device. As in the usual practice, each of X-ray tubes 3 is housed in a suitable protecting cylinder 5 which includes a window, not shown, forthe passage of the X-ray beam. Each of theX-ray machines is contained in a housing 6. A partition Wall 7 is provided in each of housings 6 to divide the internal space thereof into la machine compart- 'and 26. v steam iscir'culated through coil 20 -by -means Vof ment 8 and an operators compartment 9. The walls forming compartments 8 are preferably of such a nature to give the required protection.

Each of transformers 1 has its low side connected through cables 10 to a current supply and its high side connected through insulated conductors 1l to the input side of its rectifying device 2. In veach of Figs. 1 and 2 the output side of the rectifying device 2 is connected through insulated conductors 12 to the terminals of X-ray tubes 3, and also through insulated conductors 13 to the pair of metallic spheres 4. The meters, switches, controls, etc., usually forming a part of such X-ray machines 'are llocated inlcompartments 9 and are generally indicated by numerals 14. No effort has been made to show the connections of meters, switches, controls, etc., 14 as such connections are well known and Jform no part of the present invention.

In each of Figs. 1 and 2 a unit 15 is shown as positioned lbeneath spheres 4 and `:between transformer `1 and rectifier 2. Units 15 serve to circulate, dehumidify, deionize, heat and remove `the -dust from Athe air in their respective apparatus compartments 8. Each of units 15, (see Fig. 3) includes a casing 16 `having an air inlet 1'7 near its bottom and an airoutlet, not shown, Vnear its top. Within'each of casings 16 is a dehumidifying -coil 18, a fan 19 or similar air circulating means,

a heating coil 20, a dust removing means 2-1, a pan 22 for catching the water separated fromthe air passed through unit y and a pipe 23 for passing this water to the sewer or other place of disposal. 'Baiile plates 24 assure the air passing through the whole of coils 18 and 20 and also serve to support fan 19. Coils 18 and 20 are preferably nned to provide extended contact surfaces vfor the air passing therethrough. Dust removing means 21 may be of any well known construction and `may be of the vlter type or of the oil film type. Cooled dehumidifying medium is circulated through coil A18 by means of pipes 25 Heating -medium such as hot wateror pipes 27 and 28.

lIn Fig. -1 -the valve29 which controls the Ainlet to dehumidifying coil 118 is operated by a diaphragm 30 which is connected by capillary tube 31 to a settable -humidity sensitive control-device 32. The valve 33 which controlsthe inlet to the heatingcoil 20 isloperated by a diaphragm 34 which is connected bycapillary tube 35 to a settable temperature sensitivecontrol device 36.

In Fig. 2 Vthe valve 37 which controls the inlet to the-dehumidiiying coil 18 is operated by a diaphragm 38 which is connected by capillary tube 39 to-asettable control device 40. Control device 40 preferably includes an air-compressingmeans and voltage-sensitive'fmeans.for controlling the operation of `the air compressing means. Control device `40 has its voltage sensitive-means connected to spheres 4 throughconductors 41. The vvalve 42 which controls the inlet tothe heating coil 20is operated by a diaphragm 43 which is connected by capillary tube 44 to a settable temperature sensitive control device 45.

The X-ray machine of Fig. 1 is operated as in the-usual practice, however, Aprior to the commencement of operation the fan 19 of unit 15 is started to set up the desired circulation of the air incompartment 8,humidity sensitive control device 32 set tothe desiredrelative.humidity value, and "temperature sensitive controldevice 36 set to @the -desired L-temperature value. Humidity 4sensitive device k32 is preferablyfset tomaintain Yfalls to a-predetermined value.

the relative humidity of the air in compartment 8 well below the relative humidity value at which trouble is experienced, for instance, device 32 may be set to prevent the relative humidity from exceeding The temperature sensitive device 36 is preferably set to prevent the temperature of the circulated air falling below the :average temperature for 'the particular season. Fan 19 will draw air into unit 15 through air inlet 17 and pass such air through dehumidifying coil 18,

heating coil 20 and dust removing means 21 to the outlet of unit 15. From the outlet of unit 15 the air will pass upwardly and come into contact with spheres 4. After striking the top of compartment 8 the .air will move to the opposite wall and from thence Will be deiiected back toward unit 15 and again drawn into unit 15. It is 'to be noticed that the circulation set up by unit 15 yis such "that dust free air is constantly circulated around all parts of the apparatus so that excessive ionization ofthe air around the exposed parts ofthe apparatus, for instance,-spheres4, is avoided. It is also to be z'noticed that `the 'air 'in passing through Ivunit 315 comes in contact with grounded closely spaced metal vsurfaces of lextended area and in so doing fis effectively deionized.

When the relative humidity is above-thedesired value, humidity sensitive -control device '32 will through capillary-tube`3`l and'diap'hragm'BO open valve 29 to allow circulation 'of the dehumidifying medium through coil I118. rIhe air in passing yin contact with the iins ofIcoil 1:8 Willlbe-cooled-and some yof the moisture thereof 'will :be condensed. This moisturewill separate out on k'the iinsofcoil 18 and fall into Epan 22 `from which it leaves the unit through pipe 23. The cooling of the air will be sensed by controlfdevice v36 which through capillary tube 35 and diaphragm 34 ywill open valve 33 to allow steam or other heating medium to circulate throughcoil 1-9 and thereby'heat the air back to the desired temperature. Fan 19 is Ikept rin `operation as 'long las the Xeray vmachine is-used.

The apparatus Vshown in Fig. 2 operates `substantially Vas just Adescribed with the exception that control device 40 is set-to open-valve 37 when the-voltage across the -terminals of X-1'aytube `3 The voltage -value to which control device40 is setfis preferablya value at which the X-ray machine 'canbe Isuc- -cessfully operated 'but Lwhic'h is less than #the optimum value.

Although -in Fig. '2 control device is shown las connected vacross spheres 4litimay-beconnected across any desired-points on the high lside l'of the circuit. Thus it may be connected across 'the 'input of rectier 2 or across the outputof transformer l. Also if-desiredcontrol 40 may'include an element sensitiveto current variations instead of an element sensitive't'o voltage'variationsand if so arranged may be .connected to the input of transformer las shown in'Fig. 4. Other changes may be made withoutdeparting from theinvention as deiined in the appended claims.

I claim:

1. In combination with X-ray apparatus, Va

.housing therefor, -means for .continuously ycircuflatingtheair'in saidV housing andmeans for modifying the moisture content of said air.

2. In combination `with X-ray rapparatus, a housing therefor, `means for continuously-,circulating the air in said fhousing, -meansforremovsing dust from'said: circulated airfmeans for'modifying the moisture content of said air and means for heating said modified air.

3. In combination with X-ray apparatus, a housing for said apparatus, means for continuously circulating` the air in .said housing and means for preventing the relative humidity of said` air from exceeding a predetermined value.

4. In combination With X-ray apparatus, a

`housing for said apparatus, means for continuously circulating the air in said housing, means for modifying the moisture content of said circulated air, and settable means adapted to control said moisture modifying means to prevent the relative humidity of said circulated air from exceeding a predetermined value.

`5. `In combination with X-ray apparatus, a housing for said apparatus means for continuously circulating the air in said housing, means for modifying the moisture content of said circulated air, settable means adapted to control said moisture modifying means to prevent the relative humidity of said circulated air from exceeding a predetermined value, means for heating said circulated air, and means adapted to control said heating means to maintain said circulated air at a predetermined temperature.

6. In combination with X-ray apparatus and the energy circuit therefor, a housing for said apparatus, means for continuously circulating the air insaid housingyandmeans affected by changes in the energy flow in said energy circuit for preventing the relative humidity of said `air from increasing to values at which the normal operation of said apparatus is interfered with.

7. In combination with X-ray apparatus and `the energy circuit therefor, a housing for said apparatus, means for continuously circulating the `air in said housing, `means for modifying the moisture content of said air, and settable means affected by the energy flow in said energy circuit operable to control the functioning of said moisture content modifying means.

8. In combination with X-ray apparatus and the energy circuit therefor, a housing for said apparatus, means for continuously circulating the air in said housing, means for modifying the moisture content of said air, settable means af-.`

fected by the energy flow in said energy circuit operable to control the functioning of said moisture content modifying means, means, for heating said circulated air, and settable means for controlling the functioning of said heating means.

9. In combination with X-ray apparatus which includes an energy circuit and an X-ray tube, a housing for said apparatus, means for circulating air through .said housing, means for modifying the moisture content of said circulated air, and means connected to said energy circuit at points at substantially same potential as terminals of said X-ray tube for controlling the functioning of said moisture content modifying means.

10. In combination with X-ray apparatus which includes an X-ray tube and an energizing circuit, a housing `for said apparatus, means for continuously circulating the air in said housing, means for modifying the moisture content of said circulated air, and settable means connected to said energizing circuit at points substantially the same potential as the terminals of said X-ray tube for controlling the functioning of .said moisture modifying means, said settable means being effected by voltage variations.

11. In combination with X-ray apparatus which includes an X-ray tube and an energizing circuit, a housing for said apparatus, means for continuously circulating the air in said housing, means for modifying the moisture content of said circulated air, settable means connected to said energizing circuit at points at substantially the same potentials as the terminals of said X-ray tube for. controlling the functioning of said moisture modifying means, said settable means affected by voltage variations and means for heating said circulated air.

HAROLD R. AUSTIN. 

